1. Field of the Invention
The invention relates to a gas solenoid valve and, more particularly, to a closed rotary gas solenoid valve for gas flow control.
2. Description of Related Art
A guardless solenoid electromagnet structure employed in a current gas solenoid valve has a flatter pull characteristics, has a smaller attraction force, has a large power loss, typically cannot execute concurrent closing of the gas pipeline, and has the characteristics shown in FIG. 1. Another type of gas solenoid valve adopts a solenoid guarded electromagnet, which has a rather steep pull characteristics as shown in FIG. 2. Due to the constraint of the power consumption and bulk factors, when a larger flow is needed, an aperture enlargement of the gas solenoid valve and elongation of the operating stroke are required. A further type of the gas solenoid valve employs an epsilon structural clapper electromagnet having a rather steep pull characteristics. When the operating clearance is enlarging, its attraction attenuates rapidly, and the solenoid valve is unable to realize the linear regulation of gas via the continuous current control, while the electromagnet can only reside in on-off state via the input of the square wave current to the coil, to attain the goal of the gas regulation through a variation of on-off time ratio of the electromagnet by changing the duty cycle of the on-off time. Using this switch regulation mode, a gas pulsation shall be generated in regulation, thereby the problems of the solenoid valve abrasion due to the frequently mechanical vibration of the electromagnet, and the intrinsic vibration frequency of the electromagnet, must be lower than the input current frequency occurred. If a closing function is concurrently operated by the solenoid valve, since at this time the electromagnetic attraction force is a minimum, difficulties shall appear when a closing elastic force is needed. The force exerted on the valve member by the compressed gas and the viscosity force of the rubber valve member have to be overcome. When more gas is required, diameters of the valve port and rubber valve member should be enlarged, the armature stroke has to be elongated, and the power loss, weight and volume of the electromagnet must be increased. At this moment, normal operation cannot be performed due to the extremely low intrinsic vibration frequency of the electromagnet.
The main object of the invention is to provide a rotary gas solenoid valve having a low power loss, a large aperture and a long operating stroke.
Another object of the invention is to provide a double closure continuous controlled gas solenoid valve.
A rotary gas solenoid valve provided by the invention comprises a valve casing installed with an inlet and an outlet. A guarded rotary electromagnet is mounted on a side of the valve casing. The guarded rotary electromagnet comprises an iron core, a coil, a rotary armature, and a seating. A valve support is fastened at the position of an axial end of the rotary armature shaft of the electromagnet corresponding to the inlet or outlet valve port. A valve member is mounted on the valve support.
Another rotary gas solenoid valve provided by the invention comprises a valve casing installed with an inlet, an outlet, a coil, a rotary armature, and a seating. A valve support is fastened at the position of the axial end of the rotary armature shaft of the electromagnet corresponding with the inlet or outlet valve port. A valve member is mounted on the valve support. A guardless rotary electromagnet is also mounted on another side of the valve casing. The guardless rotary electromagnet comprises an iron core, a coil, a rotary armature, and a seating. A valve support is fastened at the position of an axial end of the rotary armature shaft of the electromagnet corresponding with the inlet or outlet valve support.
According to the rotary gas solenoid valve, a reset spring is mounted in the guarded or guardless electromagnet, one end of the spring being fixed on the iron core or the seating and another end of the spring being mounted on a side of the rotary armature or an arm fastened with the axial end of the armature shaft.
According to the rotary gas solenoid valve, a rubber-sealing ring is mounted therein between the shaft of the rotary-type armature and a bearing positioning hole of the valve casing.
According to the rotary gas solenoid valve, an adjusting screw is installed therein on the reset spring mounted in the guardless rotary electromagnet.